Many toner containers are shaped like conventional bottles, where a cylindrical body containing a powder is joined with a smaller diameter bottle opening by a conically-shaped converging shaped like a funnel that helps to contain and direct the toner discharge flow. This classical bottle design works well with liquids. However, when the bottle-like cartridge is filled with a powder comprising, for example, toner particles, the substance exiting process is often hampered by well-known effects, known as “bridging” and “rat-holing” effects, which effects are inherent exit flow problems of all symmetrically-shaped funnel-like containers.
The foregoing bridging effect occurs when the toner powder forms internal spherical structure (arches), thus restricting or completely blocking the flow. When this happens in an image forming device such as an xerographic machine, the bottle must be removed from the image forming device (xerographic machine), then shaken well and reinserted into the image forming device. This process results in substantial annoyance or irritation in the machine users or customers.
Further, the foregoing rat-holing effect occurs when, due to the different friction forces between toner particles with other toner particles and toner particles and bottle walls, a hole is formed in the toner mass at the bottle exit. This hole is also shaped like a funnel in the dense, plug-like toner mass that remains in the bottle after all fluidized toner is discharged. Thus, the toner that forms the “rat-hole” remains in the bottle, unused and, as far as the customer is concerned, is wasted.
One known solution to these problems is to equip toner containers with internal agitators. However, this solution is costly compared to a simple blow molded toner bottle design.